Reflow soldering apparatus

Abstract

A reflow soldering apparatus using circulated heated gas to solder electronic components to a printed circuit board while transporting the printed circuit board mounted with electronic components on a conveyor chain. A plurality of gas passages for inflow of heated gas which have openings facing the circuit board, are provided at intervals in the transport direction of the conveyor chain. A first passage is provided for the flow of heated gas into the fan from an opening different from the opening for inflow and formed in the intermediate portion of the gas passage, and a second passage is provided for the flow of heated gas into the fan from openings formed on both ends of the gas passage.

What is claimed is:  
     
       1. A reflow soldering apparatus using circulated heated gas to solder electronic components to a circuit board while transporting said circuit board mounted with electronic components on a conveyor through a heating chamber, said reflow soldering apparatus comprising a plurality of gas passages formed at intervals along the transport direction of said conveyor, each said gas passage having an opening for inflow of heated gas on the side facing said circuit board, and a first passage for the flow of heated gas into a blowing means from an opening different from said opening for inflow and formed in an intermediate portion of said gas passage, 
       wherein said reflow soldering apparatus has a second passage for the flow of heated gas into said blowing means from an opening formed in an end portion of said gas passage.  
     
     
       2. A reflow soldering apparatus according to  claim 1 , wherein said gas passage is a long, narrow passage transverse to the conveyor transport direction. 
     
     
       3. A reflow soldering apparatus according to  claim 1 , wherein a gas passage for blowing heated gas onto said circuit board is formed between said gas passages for inflow of heated gas. 
     
     
       4. A reflow soldering apparatus according to  claim 1 , wherein a gas passage for blowing heated gas onto said circuit board is formed between each of said gas passages for inflow of heated gas. 
     
     
       5. A reflow soldering apparatus according to  claim 3 , wherein said gas passage for blowing heated gas is a long, narrow passage transverse to the conveyor transport direction. 
     
     
       6. A reflow soldering apparatus according to  claim 1 , wherein said blowing means has intake openings on both opposite sides, and the heated gas flowing through said first passage is drawn into one of said intake openings, and the heated gas flowing through said second passage is drawn into the other intake opening. 
     
     
       7. A reflow soldering apparatus according to  claim 1 , wherein said blowing means has intake openings on said circuit board side and on the opposite side, and the heated gas flowing through said first passage from said opening formed in the intermediate portion of said gas passage is drawn into said intake opening provided on the circuit board side of said blowing means, and the heated gas passing through said second passage from said opening formed in the end portion of said gas passage is drawn into said intake opening provided on the opposite side from the circuit board. 
     
     
       8. A reflow soldering apparatus according to  claim 1 , wherein said blowing means has an intake opening on one side. 
     
     
       9. A reflow soldering apparatus according to  claim 1 , wherein said blowing means has an intake opening on a circuit board side, and the heated gas flowing through said first passage from said opening formed in the intermediate portion of said gas passage is drawn into said intake opening of said blowing means. 
     
     
       10. A reflow soldering apparatus according to  claim 1 , wherein said blowing means has an intake opening on said circuit board side, and the heated gas flowing through said first passage from said opening formed in the intermediate portion of said gas passage is drawn into said intake opening of said blowing means, and the heated gas passing through said second passage from said opening formed in the end portion of said gas passage is drawn into said intake opening of said blowing means. 
     
     
       11. A reflow soldering apparatus according to  claim 1 , wherein said blowing means is a fan or a blower. 
     
     
       12. A reflow soldering apparatus according to  claim 11 , wherein said fan is a turbofan or a multiblade fan. 
     
     
       13. A reflow soldering apparatus according to  claim 1 , wherein nitrogen gas is employed as said gas. 
     
     
       14. A reflow soldering apparatus according to  claim 1 , wherein air is employed as said gas.